Pando is a mega organism made up of 106 acres of quaking aspen that share the same DNA with a single root.
In the Wasatch Mountains of the western US, on the slopes above a spring-fed lake, inhabits a single giant organism that provides an entire ecosystem that plants and animals have depended on for thousands of years.
Found in the state of Utah, "Pando" is a 106-acre group of quaking aspen clones.
Although it looks like a forest of individual trees with striking white bark and tiny leaves that flutter in the slightest breeze, Pando (Latin for "I spread out") has 47,000 genetically identical stems that emerge from a network of interconnected roots.
This single genetic individual weighs about 6 million metric tons. By mass, it is the largest single organism on Earth.
Poplar trees tend to form clonal stands elsewhere, but what makes Pando interesting is its sheer size. Most clonal aspen stands in North America are much smaller, with those in the western United States averaging 3 acres.
Pando has been around for thousands of years, potentially up to 14,000 years, even though most stems only live for about 130 years. Its longevity and remoteness mean that an entire ecosystem of 68 plants and many animals have evolved and remained in its shade.
This entire ecosystem depends on the aspen remaining healthy and upright. But while Pando is protected by the US National Forest Service and is not in danger of being cut down, it is at risk of disappearing due to several other factors.
This is the warning from Richard Walton, a postdoctoral research associate at the University of Newcastle (UK). He has been studying Pando for years and has found overgrazing of deer and elk one of the biggest concerns for their survival.
The scientist warns that as wolves and cougars have ceased to be natural predators in the area, the herds of deer and elk are now much more significant; he also highlights that these animals seek refuge in Pando because of the government protection that the organism has away hunters.
As older trees die or fall, light reaches the forest floor, stimulating the growth of new clonal stems, but when these animals eat the tops of the newly formed stems, they die. This means that in large portions of Pando, there is little new growth.
The exception is an area that was fenced off a few decades ago to remove dying trees. This fenced area has excluded elk and deer and has successfully regenerated new clonal stems, with dense growth known as the "bamboo garden."
In addition, climate change and disease are other risk factors for Pando. Older stems, for example, are affected by conditions such as soot bark canker, leaf spot, and fungal conk disease.
While plant diseases have developed and thrived in aspen forests for millennia, the long-term effect on the ecosystem is unknown, given a lack of new growth and a growing list of other pressures on the clonal giant.
The fastest-growing threat is that of climate change. Pando emerged after the last ice age had passed and has faced a largely stable climate ever since.
It undoubtedly inhabits an alpine region surrounded by desert. It is no stranger to warm temperatures or drought. But climate change threatens the size and lifespan of the tree, as well as the entire ecosystem it supports.
Although no scientific study has focused explicitly on Pando, aspen stands have been struggling with pressures related to climate change, such as reduced water supplies and warmer weather earlier in the year, making it difficult for them to trees form new leaves, which has led to declines in cover.
With more competition for increasingly scarce water resources, temperatures expected to continue to rise to record levels in summer, and the threat of more intense wildfires, Pando will undoubtedly have a difficult time adjusting to these rapidly changing conditions while maintaining its size.
The good news is that this mega organism is no stranger to rapid environmental changes and has managed to survive. So, despite all the concerns, there is hope for Pando's survival, especially if scientists can better understand how he works to recover.
For that, Walton says, it is essential that Pando be better known. That is why he highlights the work of an activist group called "Amigos de Pando," whose objective is to make this mega organism accessible to all thanks to 360 video recordings.
"It is these moments that remind us that we have plants, animals, and ecosystems that are worth protecting. In Pando, we have the rare opportunity to protect all three", highlights the scientist.